[1] Natl Inst Infect Dis, Dept Virol 2, Musashino, Tokyo 2080011, Japan
[2] Natl Inst Infect Dis, Ctr Pathogen Genom, Musashino, Tokyo 2080011, Japan
[3] Natl Inst Infect Dis, Div Biosafety Control & Res, Shinjuku Ku, Tokyo 1628640, Japan
[4] Univ Tokyo, Dept Vet Microbiol, Grad Sch Agr & Life Sci, Bunkyo Ku, Tokyo 1138657, Japan